Thebmodtnamic pbocess



March 8, 1932. B. c. voN PLATEN 1,848,918

' THERMODYNAMIC PROCESS Original Filed Marc}; so. 1927 7 Sheets-Sheet 1 ATTORNEY JAM! ' March 8, 1932. c. VON PLATEN" 'THERMODYNAMIC PROCESS Original Filed March so. 1927 7 Sheets-Sheet 2 were March 8, 1932.

B. c. VON- PLATEN 1,843,918v

-THERMODYNAMIC PROCESS Original Filed March 30. '1927 7 Sheets-Sheet 3 /a .7 20 3a 4a 50 {a 70 aa 9010b //0 /20 430 Ma. /J'0 4:0 /70 x80 March 8, 1932. B. C. VON PLATEN I ,9

r THERMODYNAMIC PROCESS *Origiri al Filed March 30, 1927-v 7 Sheets-Sheet 4 4/ ATTORNEY March 8, 1932 B. c. VON PLAfEN THERMODYNAMIC-PROCESS 7 Sheets-Sheet 5 Original Filed March 30, 1927 NVENTO M g BY i' A'I TORNEY March 8, 1932- B. c. VON PLATEN THERMODYNAMIC PROCESS Original Fil-ed March 50. 1927 '7 Slxeets-Shee'c 6 INENTOR In: ATTORNEY March 8,1932. 5. 'c. VON PLATEN 1,8 8,9 8

THERMODYNAMIC PROCESS Original Fild March 30. 1927 7 Sheets-Sheet '7 INVENTO T a /Mz/m% B fir ATTORNEY Patented Mar. -8, 1932v I UNITED STATES PATENT OFFICE?- ram'zan cam. vex rm'ramor srocxrromm, swnnnir', assrcnon 'ro nrnc'raowx smwnr. ooBroRA'rroN, or. new ironic, n. 1., a conrona'rron or DELAWARE 'rnnmrommmrc rnocnss Application. filed. March 80, 1927, Serial 110.179,!375, and in s'weden March $1, 1926. Renewed Iebruary 16, 1931.

A The-object of the present invention is to provide an improved process of refrigeration. I

The improved process will. be readily understood by reference to'the. following; descrip-' 5 tion taken in connection with theaccompanying drawings, on which:

Fig.1 is a graphic representation of the cycle process of a refrigerant in an ordinary" pressure, but also, that all the heat which is type of, absorption refrigerating apparatus Fig. 2 is a. graphicv representation of the cycle process of a refrigerant in accordance with the present inventlon;

Fig. 3 isa graph'c representation of a modified cycle process in accordancewith the in- .vention; a

Fig. 4 is a diagram of-curves for conditions of difl'erent fluids showingthe relation of such curves and conditions to theinvention; it

'Fig. 5 is a diagrammatic illustration of apparatus for carrying out the invention;

Fig. 6 shows, more or less diagrammatically, an apparatus for carrying out the invention embodying no moving parts;

Fig. 7 shows diagrammatically an apparaciroulations for four fluids;

Fig. 8 shows a. modification of the apparatusof Fig. 7;

Fig. 9 shows graphically the cycle progress of one fluid in the process of the apparatus .of Figs. 7 and 8; v

Fig. 10 shows graphically the cycle progress of a second fluid of Fig. 7 x

Fig..11 shows a graph of the process of a and t Fig. 12 is a diflerent process graph under different conditions.

Referring more particularly to'Fig. 1, the abscissas represent values of absolute temperature and ordinates represent the logarithm of values of pressure. In the diagram: 0 represents the condition in the evaporator; 6 represents thecondition in the absorber; c

i represents the condition in the boiler; and d represents the condition in the condenser.

The lines a.-d and b0 are drawn straight and parallel-which is not strictly in accordance with actual conditions but is sufficiently close for present purposes.

tus for carrying out the invention comprising fluid in a system under diflferent conditions 'The process of the present invention is diagrammatically illustrated in Fig. 2. It

liberated in the condenser. is conducted to the .boiler. In every absorption refrigerat mg process, where the heat liberatedin the condenser is conducted to the boiler either by means of another process or, as in the process a-bcd-a, spontaneously, considering the process as a whole, the highest. conceivable efliciency 1 is:

1 I Tc; TD 0 Tan-T. a

when T represents the absolute temperature of the evaporator, T represents the absolute temperature of the absorber; and T represents the absolute. temperature of the boiler.

From this equation it will be seen that the temperature of the condenser is not included efliciency thus is independent. This is manifestly the most important feature of this temperature, oras shown in Fig. 3, a process a-"-b;0d+a, where the temperature of the condenser is a little higher than that of the boiler, which in the practice always will be the case. v I If in a process ab-cda, in accordance in the equation, of which temperature the with Fig. 2, the temperatures of the evaporator and the absorber are given, the efliciency is determined only by the temperature of the I boiler. This again is a function only of the inclination of the lines of state a-"d and 6-0. In general a little alteration in the in-' clination of the lines corresponds to a relatively great alteration in the boiler-temperature. Because it is possible to vary the inclination of the lines freely and arbitrarily within certain bounds, the efficiency of an absorption refrigerating apparatus working in accordance with the diagram ab--cd-a,

in Fig. 2, may be freely varied within certain bounds.

In Fig. 4 the (log. pT) -curves for ammonia (NH dissolved in different liquids are shown. From the figure it will be seen that the curve is steeper for ammonia dissolved in calcium chloride and water (CaCl +H O) than for ammonia dissolved in ure water (H O).

y varying the percentage of calcium chloride it is possible to vary the inclination of the (log. p-T) -curve within the bounds which are decided by the two curves mentioned. In the figure some other curves-are shown for ammonia dissolved in other media such as phenol (C H OH), glycol .1 and others." I It is clear that if the media, which corresponds to the line a-d, do not mix at the boiler-temperature with thosecorresponding to the line 6-0, these media may be allowed to comeinto direct contact with each other at the point 001. If, on the other hand, they mix with each other, they can not be allowed to come into direct contact, but only gaseous ammonia should be conveyed from 0 to d. It is also possible to arrange that not more water-vapor or vapor of other media will be conveyed from c to (1 than from a to b.

In Fig. ithe (log. p-T) -curves are shown for ammonia dissolved in the following media, which may be used in processes according to the present invention:

(1) Water-solution of strontium chloride (SrCI saturated at 15 C. and 37 f 0.,

(2) Water-solution of ammonia nitrate (H NNO saturated at 15 0.,

In the diagram the chemical symbols of the substances are given with indications to the respective curves. It will be clear from the diagram that,for the phase d-cd, the combination NH -H NNO is suitable and, for the phase bpd, forinstance NI-I 08:012- w p I -'As further suitable substancesmay be mentioned: g

-(8) Water-solutions of inorganic ororganic salts, preferably chlorides and nitrates of lithium, calcium, strontium, zinc, copper, etc.

(9) Waterfree salts, for instance ammonia nitrate, (10) Organic or inorganic chemically combined liquids such as Water, glycol,

'glycerine, phenol, amines, CH-combinations,

etc.

(11) Mixtures of these matters with each other or with other matters, etc.

In the following, some apparati working in accordance with diagrams a-bcda will be described.

In F 5 is shown a diagrammatic view of such an apparatus. Letter A designates the evaporator corresponding to the point a in the diagram a/bcd a, and B the absorber, corresponding to the point b in the same diagram. The vessel CD, which may be called the boiler, is divided into two parts,

C andD by means of a wall V. The boiler I corresponds -to the point ed in the diagram. In this case an absorber corresponds to what was previously designated by the word condenser. A lively circulation of ammonia and ammonia-nitrate is going on between A and D through the pipes R and R and of ammonia and calcium chloride through the pipes R and R Through the pipes R and R gaseous ammonia and inert gas are circulating, which latter, in known manner, equalizes the diiferences in the partial pressures of the. ammonia in A and B. These circulations, for the maintenance of which manifestly only very little work is required, are, in the schematical Fig. 5, considered to be kept going by means of the pumps P P P P and P R and R like R and R are arranged in thermal contact with each other, so that heat is exchanged between the counter'fiowing' liquid-streams. In the same manner the gas c0nduits'R and R can be arranged in thermal contact with each other. For the rest, the working process of the apparatus can be directly read ofi the diagram ab-ccZ-a. Thus gaseous ammonia is conducted from the right gas chamber C of the boiler to the left one D and heat through the-wall V from D to C. At the same time heat is to be supplied to the boiler from outside. By means of the gas circulation .be-

tween the vessels A and B gaseous ammonia is conducted from A to B, corresponding to the gas transmission from a to b in the diagnam ab ad-a.

In the diagram of Fig. 4, the ammonia-ammonia nitrate curve, which is the a-d curve of this apparatus, crosses the ammonia-calcium chloride 37 curve, as can be readily seen. The crossing point of these curves is the condition of vessel CD of the apparatus of Fig. 5.

In order to make the above described ap- 'out over the discs E In Fig. 6 such apparatus is shown. The

reference characters A, B, CD, C, D, R R

R R It and R correspond to the reference characters in Fig. 5. The liquid circulation between A and CD is maintained in the following manner:

Gas leaves the gas chamber C through the pipe R, which ends in the u wardly extending part of pipeR which t erefor-e may be called RR Thus in the pipe RR 'a mixture of gas and liquid is obtained, which mixture will move upwardly. The liquid thus flows in the vessel D, where that gas which is not already absorbed in BB will be absorbed.

The liquid circulation between B and CD 'is obtained in the following manner:

The upwardly extending part of pipe R is arranged as a coil P around the Vessel D. In P the liquid will boil by means of heat supplied from D and-from the electric heating device F. Through P the liquid thus seethes up into vessel C.

The gas circulation through R, and R is obtained by choosing an inert gas which has higher molecular weight than ammonia, for instance nitrogen. I

By means of the heating device F the necessary heat is supplied as well to C and D, that is CD, as to P. The heat may, of course, be supplied in other manners, for instance by means of a gas burner or the like.

Thus it will readily be seen that the process and parts of Fig. 6 are the same as of Fig. 5, the difference being that the circulations are made by means of internal factors instead of being maintained by pumps.

In Fig. 7 another particular form of construction of an absorption refrigerating apparatus is shown, in accordance to the above discussed theories.

.00 represents a substance which dissolves water unlimitedly, but only a little ammonia or no ammonia at all. The letter y designates another substance, which dissolves water and ammonia but not the substance Thesubstance it may be a base, suitably caustic potash or sodium hydrate dissolved in water; and the substance g may for instance be aniline. The apparatus consists, as in the foregoing case, of three vessels A, B and CD. In the vessel A heat is taken up atlow temperature, in B this heat isdelivered to the surroundings and heat is supplied to CD at high temperature.

In the vessel CD the water, under the influence of heat is transferred from the base to the aniline. Aniline and water flow through pipe R to the vessel B, where the ammonia coming from A through pipe R is absorbed. Aniline, water and ammonia flow through pipe R .to vessel A. -Here the water is taken up by the base coming from CD through pipe -R2, wherefore the ammonia departs in gaseous condition at low temperature and the aniline again is transferred to CD through pipe ,B The base with the water taken up in A .is again transferred to CD through pipe R R R R R and R are arranged in thermal contact with each other, so that heat is exchanged between the counterflowing liquid-streams. The liquid circulation is, according to this schematic diagram, maintained by the pumps P P P P and P In Fig. 8 another apparatus is diagrammatically shown which differs veryv little from the foregoing. In this case water is separated in B from the aniline-water-solution, which comes through R The water in B absorbs ammonia coming from A through 'R, whereafter the same flows on to A, where it is directly mixed with the base coming from CD through R The ammonia is expelled in A in gaseous condition, whereafter the water and the base return to CD .through R Here the water is taken upby the aniline coming from B through R in order to-again be expelled in B. The circulation in this schematic figureis indicated as being maintained by means of the pumps P P P P and P In the (log. p-T) -diagram in Figs. 9-12 are shown the cyclic processes in the two lastmentioned apparati, and second, of the water.

- It is assumed that all ammonia is evaporated at T and con- 'tively coming from the vessel B is mixed with the solution in A. It Will be under-. stood that this discontinuity imparts an irreversible reaction and a loss, which would be avoided, if, at the communication from b to a (Fig. 9), that, is from B to A ,(Figs. 6, 7 and 8), water would be allowed to continuously flow over from the NH +H O aniline: solution'or the NH +H O-solution respec-' tively to the lye, but only so much water that the pressure of the ammonia would be constant from b to a, that is from B to A. As before, the ammonia would evaporate at a and condense at b and its alteration of condition would, in the diagram, be a straight first, of' the ammonia 100 I line between a and b. dotted.) V

More interesting and more important is the alteration of the state of condition of the water. The apparatus corresponding to Fig. 7 will first be discussed. In its passage from B to A the water is dissolved in aniline-and ammonia. In its passage from A to CD caustic potash and sodium hydrate are dissolved in the water. One will find a difference between the steam-pressure-curve for the water dissolved in aniline and the ord'inary steam-pressure-curve for water, in which a salt is dissolved. It will be shown that this difference of the steam-pressurecurves is of the same importance for this process as for the aforementioned processes ab--0(l--a for instance in Fig. 3.

' In Fig. 10 the diagram for the cyclic process of the water is shown, I-IIIII-IV V-VI-VII-I. The same numerals occur also in Fig. 7. The pressures and temperatures at the different points may be indicated as 12 -19 etc. and T;T etc. In the vessel CD water is driven from the lye to the aniline by means of the power p p The decrease of the pressure p -p is partly of irreversible nature and causes a loss, which is explained in that water and aniline of the state III flow in into the vessel B (Fig. 7) and is there mixed with the liquid rich in ammonia. The rest of the decrease of pressure is a consequence of absorption of ammonia in the vessel B. The decrease of pressure p pv is'of irreversible nature and 'causes a loss, which is ex lained-in that water-l-aniline+ ammonia o the state V flows in into the vessel A and is there mixed with the liquid richer in ammonia. By means of the power p pv the water is driven from the aniline and ammonia to the lye. From this diagram the importance of the difference between theinclination of the steam-pressure-c'urves will be seen, because 1f the curves were parallel,

a diagram corresponding to Fig. 11 would.v

be obtained instead. The ressure difference between the points VI and VII is negative in this case, which means that energy must be released in order to transfer the water to the lye in the vessel A. Further it will be seen from the diagram of Fig. 10 that the oint of intersection between the lines I- II and II-III corresponds to the point 0.2 in the aforementioned rocess a-b-cd--a according to Fig. .3. s the ammonia ne'a-r ed, in

' the figure mentioned, is transferred at one and the same temperature and about the same pressure from the liquid phase b0d to a0d, the water between I and II is transferred at one and'the' same temperature and about the same pressure from the liquid phase I-VII to II-III. 3

If water is expelled from the aniline in the vessel B, so that only small amounts of aniline are considered to follow the water and (In Fig. 9 this line is '12. The line IV- is ammonia from IV to V (that is from vessel B to A in Fi 8), the diagram in Fig;10 instead gets t e a earance shown in Fig. here steeper than in the diagram according to Fig. 10, because the aniline is not present.

It is clear that the last described principle,

as the foregoing, also can be carried out for generating work. If, for instance, it is arranged so that in the vessel A (Figs. 5, 6, 7 or 8) the pressure of the ammonia is higher than in B, work is obtained, when the ammonia is transferred from A to B. The higher pressure in A may be obtained by increasing the concentration of the ammonia in A and by increasing the temperature in A. If the temperature in A is thus increased to the temperature T of the surroundings, which is the most natural, when the'apparatus is used only as a work-generating machine, the. pressure in A is increased, whereby, as already mentioned, work is obtained when the gas is transferred to the lower pressure in B. A machine according to Fig. 5 can for instance work as a power generator, if in the conduit 8 a power machine is inserted, in which case a pressure equalizing gas is not used and the conduit R and the pump P5 are unnecessary. With a machine in accordance with the showing of Fig. 7 a power machine forthe same tween the vessels A and B. Power generation can, also be effected bymeans of partly converting the heat Eenergy. transferred to the vessel B into work by known expedients. Work-generating machines of this kind are purpose can be inserted in the conduit R .be-'

well-known and it is not necessary to explain their construction more closely in this connection.

The above mentioned thermodynamic processes can, of course, also be used in combination with heat aggregates, whereby the heat conducted to the vessel B is directly used for heating purposes.

What I claim is:

1.- The proceess of refrigerating which comprises circulating refrigerant in a solution having a given pressure-temperature curve for conditions of operation, transfer ring the refrigerant to a second solution having a given pressure-temperature curve for conditions of operation which crosses the first-mentioned curve and effecting the transfer substantially at the conditions represented by the point of crossing of the curves, circulating the refrigerant in the second solution into heat exchange relation with the objective of refrigeration, expelling the refrigerant from the second solution in heat exchange relation with the objective of refrigeration to take up heat and-transferring the refrigerant to the first-mentioned solution.

2. The process of refrigerating which comprises circulating a fluid in a solution fluid to a second solution having a given curve pressure-temperature curve for conditions of operation which. crosses the first-mentioned and effecting the .transfer substantially at the conditions represented by the point of crossing of the curves, circulating fluid in the second solution into heat exchange relation with the objective of refrigeration,

causing a change of state of said fluid in heat exchange relation with the objective of refrigeration in order to take up heat and transferring said fluid back to the first-mentioned solution.

3. Refrigerating apparatus comprising an absorber containing refrigerant in a solution having a given pressure-temperature curve for conditions of operation, a generator-absorber, means to clrculate said solution between the first-mentioned absorber and the enerator-absorber, an evaporator containmg refrigerant in a solution having a given pressure-temperature curve for conditions of operation which crosses the first-mentioned curve, means to circulate the second solution between the evaporator and the generator-absorber and means to convey refrigerant from the evaporator to the first-mentioned absorber. I

4:. Refrigerating apparatus comprising a generator and an absorber arranged in heat exchange relation to operate at substantially the same temperature and pressure, a second absorber, means to circulate refrigerant in solution between the second absorber and generator, an evaporator, means to circulate refrigerant in solution between the evaporator and the first-mentioned absorber and means to convey refrigerant from the-evaporator to the second absorber.

5. Refrigerating apparatus comprising a combined generator-absorber, a second evaporator, an absorber and means to circulate.

refrigerant from the combined generator-absorber to the evaporator, from the evaporator to the second absorber and from the second absorber to the combined generator-absorber.

" frigerant'in solution between the second ab 6. Refrigerating apparatus comprising a combinedgenerator-absorber, a second absorber, an evaporator, means to circulate resorber and the generator-absorber, means .to circulate refrigerant in solution between the evaporator and the generator-absorber and means to convey refrigerant from the evaporator to the second absorber.

7. The process of transforming energy which comprises the steps of circulating a fluid in a solution-having a given pressuretemperature 'curve'for conditions of operation, transferring the fluid to a second solution having a given pressure-temperature curve for conditions of operation which crosses the first-mentioned curve and effecting the transfer substantially at the condi- I tions represented by the point ofcrossing of the curves, expelling the fluid from the second solution and moving said fluid back into the first-mentioned solution.

8. The process of refrigerating which comprises circulating a. refrigerant gas in a cycle in solution in a solvent past an inert gas, said solvent being capable of holding a relatively large proportion of the refrigerant gas at a low temperature and corresponding partial pressure of the refrigerant gas, circulating tioned solvent at low temperature by means of an inert gas. I

9. The'process of refrigerating which comprises circulating a gas in a cycle in solution in a solvent capable of holding a relatively large proportion of the gas at a low temperature'and corresponding gas pressure, circulating some of the same gas in a second cycle in solution 1n a second solvent capable of I holding a relatively smaller proportion of v ,the gasa-t a low temperature and corresponding gas pressure and capable of holding a relatlvely larger proportion of the gas at a v high temperature and corresponding gas pressure, passing the'gas from the first-mentioned solvent to the second solvent at high temperature and passing the gas fromthe second solvent to the first-mentioned solvent at low temperature.

10. The process of refrigerating which comprises circulating an absorbent in a solution havlng a g ven pressure-temperature curve for conditions of operation, transferringthe absorbent to a second solution havinga given pressure-temperature curve for conditidns of operation which crosses the first-mentioned curve and effecting the transfer substantially at the conditions represented by the 'point 'of crossing of the curves, absorbing a refrigerant in said secondmsolution, circulating the refrigerant in said second solution into heat exchange relation with the objective of refrigeration and transferring the absorbent to,

the first-mentioned solution whereby said re- I frige'rant-is expelled from said second solution. v v

11. The process of refrigeration which comprises circulating an absorbent in a solution having a given pressure-temperature curve for conditions of operation,

transferring the absorbent to asecond solution having a given pressure-temperature curve for conditions of operation which crosses the first mentioned curve and effecting the transfer substantially at the conditions represented by the point of crossing of the curves, separating the absorbent from said second solution, absorbing a refrigerant in the absorbent, circulating the refrigerant in the absorbent into heat exchange relation with the objective of refrigeration, and transferring the absorbent to the first-mentioned solution whereby said refrigerant is expelled from said second solution.

12. Refrigerating apparatus comprising a heated vessel, an absorber, an evaporator, means for supplying an absorbent in solution with a first liquid to said heated vessel, means for supplying a second liquid to said heated vessel, said absorbent and said second liquid having a greater aflinity for each other at the temperature obtaining in said heated vessel than the aflinity between said absorbent and said first liquid, whereby said absorbent passes from solution. with said first liquid, to solution with said second liquid, means for I conveying a solution comprising said abtion, circulating some of the same fluid in a second solution having a given pressure-temperature curve for conditions of operation WhlCh crosses the first-mentioned curve,

transferring said fluid from one of the solu-.

tion liquids to the other under conditions to one side of the point of crossing of the curve I and transferring said fluid in the other direction between the solution liquids under conditions on the other side of the point of crossing of the curves. In testimony whereof I hereunto afiix my signature.

BALTZAR CARLvoN PLATEN.

sorbent and said second liquid to said ab- I sorber, means for supplying vaporous refrigerant to said absorber, means for conveying a solution comprising said second liquid, said absorbent and said refrigerant to said evaporator, and means for supplying said first liquid to said evaporator, said absorbent and first liquid having a greater aifinity for each other at the temperature obtaining said evaporator than the aflinity between sa1d absorbent and said second liquid whereby said absorbent passes from solution with said second liquid to'solution with saidfirst liquid and said refrigerant passes into the vapor state. 7

13. Refrigerating apparatus comprising a heated vessel, an absorber, an evaporator,

; means for supplying a first solution comprising an absorbent and a first liquid to said heated vessel, means for supplying a second liquid to said heated vessel, means for conveying a second solution comprising said absorber and said second liquid from said heated vessel to said absorber, means for'supplying vaporous refrigerant to said absorber, means for conveying a third solution comprising said absorbent, said second liquid and said refrigerant from said absorber to said evaporator and means for conveying said first liquid from said heated vessel to said evaporator.

14. Refrigerating apparatus comprising a heated vessel, an absorber, an evaporator,

means for circulating an absorbent in solu- CERTIFICATE OF CORRECTION.

Patent No. 1,848,918. March 8, 1932.

. BALTZAR CARL voN PLA'EEN.

It is hereby certified that error appears inthe printed specification of the above numbered patent requiring correction as follows: Page 5, line'43, claim 5, for "a second" read on, and line 44, for "an" read a second; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patentfifiice.

Signed and sealed this 12th day of my, A Do H932.

. M. J. Moore, (Seal) Acting Qommissioner of Patents. 

